/*
 * Copyright � 2002-2011 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

using System.Web;
using System.Web.UI;
using Microsoft.Extensions.Logging;
using Spring.Context;

namespace Spring.Web.Conversation.HttpModule;

/// <summary>
/// HttpModule for ending Conversations with Timeout exceeded.
/// </summary>
/// <author>Hailton de Castro</author>
public class ConversationModule : IHttpModule, IApplicationContextAware
{
    private static readonly ILogger<ConversationModule> LOG = LogManager.GetLogger<ConversationModule>();

    private IList<string> conversationManagerName;

    /// <summary>
    /// The Names of the <see cref="IConversationManager"/>s in the <see cref="IApplicationContext"/>
    /// </summary>
    public IList<string> ConversationManagerNameList
    {
        get { return conversationManagerName; }
        set { conversationManagerName = value; }
    }

    /// <summary>
    /// Add PostRequestHandlerExecute event to clear conversations with timeout exceeded.
    /// </summary>
    /// <param name="context"></param>
    public void Init(HttpApplication context)
    {
        context.PreRequestHandlerExecute += context_PreRequestHandlerExecute;
        context.PostRequestHandlerExecute += context_PostRequestHandlerExecute;
        context.EndRequest += context_EndRequest;
    }

    /// <summary>
    /// Disposes of the resources (other than memory) used by the module that implements <see cref="T:System.Web.IHttpModule"/>.
    /// </summary>
    public void Dispose()
    {
        //noop
    }

    void context_PreRequestHandlerExecute(object sender, EventArgs e)
    {
        if (HttpContext.Current.Handler is Page)
        {
            Page page = (Page) HttpContext.Current.Handler;
            page.Unload += page_Unload;

            if (HttpContext.Current.Session != null)
            {
                if (LOG.IsEnabled(LogLevel.Debug)) LOG.LogDebug("context_PreRequestHandlerExecute: Processing HttpContext.Current.Session");
                foreach (String convMngName in this.ConversationManagerNameList)
                {
                    if (LOG.IsEnabled(LogLevel.Debug)) LOG.LogDebug(string.Format("context_PreRequestHandlerExecute: Processing ConversationManager: {0}", convMngName));
                    IConversationManager convMng = (IConversationManager) this.applicationContext.GetObject(convMngName);
                    convMng.EndOnTimeOut();
                    convMng.FreeEnded();
                }
            }
            else
            {
                if (LOG.IsEnabled(LogLevel.Debug)) LOG.LogDebug("context_PreRequestHandlerExecute: no HttpContext.Current.Session found.");
            }
        }
    }

    /// <summary>
    /// Handles the Unload event of the page control.
    /// </summary>
    /// <param name="sender">The source of the event.</param>
    /// <param name="e">The <see cref="System.EventArgs"/> instance containing the event data.</param>
    /// <remarks>
    /// Necessary for Redirect or Abort for any reason.
    /// </remarks>
    void page_Unload(object sender, EventArgs e)
    {
        if (LOG.IsEnabled(LogLevel.Debug)) LOG.LogDebug("page_Unload HttpContext.Current.Session is null: " + (HttpContext.Current.Session == null));
        foreach (String convMngName in this.ConversationManagerNameList)
        {
            if (LOG.IsEnabled(LogLevel.Debug)) LOG.LogDebug(string.Format("page_Unload: Processing ConversationManager: {0}", convMngName));
            IConversationManager convMng = (IConversationManager) this.applicationContext.GetObject(convMngName);
            convMng.EndOnTimeOut();
            convMng.FreeEnded();
            convMng.PauseConversations();
        }
    }

    void context_EndRequest(object sender, EventArgs e)
    {
        if (LOG.IsEnabled(LogLevel.Debug)) LOG.LogDebug("context_EndRequest HttpContext.Current.Session is null: " + (HttpContext.Current.Session == null));
    }

    void context_PostRequestHandlerExecute(object sender, EventArgs e)
    {
        if (LOG.IsEnabled(LogLevel.Debug)) LOG.LogDebug("context_PostRequestHandlerExecute HttpContext.Current.Session is null: " + (HttpContext.Current.Session == null));
        if (HttpContext.Current.Session != null)
        {
        }
    }

    private IApplicationContext applicationContext;

    /// <summary>
    /// Sets the <see cref="Spring.Context.IApplicationContext"/> that this
    /// object runs in.
    /// </summary>
    /// <value></value>
    /// <remarks>
    /// 	<p>
    /// Used to obtain the instances of <see cref="IConversationManager"/>
    /// </p>
    /// 	<p>
    /// Invoked after population of normal object properties but before an
    /// init callback such as
    /// <see cref="Spring.Objects.Factory.IInitializingObject"/>'s
    /// <see cref="Spring.Objects.Factory.IInitializingObject.AfterPropertiesSet"/>
    /// or a custom init-method. Invoked after the setting of any
    /// <see cref="Spring.Context.IResourceLoaderAware"/>'s
    /// <see cref="Spring.Context.IResourceLoaderAware.ResourceLoader"/>
    /// property.
    /// </p>
    /// </remarks>
    /// <exception cref="Spring.Context.ApplicationContextException">
    /// In the case of application context initialization errors.
    /// </exception>
    /// <exception cref="Spring.Objects.ObjectsException">
    /// If thrown by any application context methods.
    /// </exception>
    /// <exception cref="Spring.Objects.Factory.ObjectInitializationException"/>
    public IApplicationContext ApplicationContext
    {
        set { this.applicationContext = value; }
    }
}
